1. Field of the Invention
The present invention relates to an interactive information providing apparatus well adapted to, for example, an in-vehicle information terminal equipped with a navigation unit.
2. Description of Related Art
In traditional information processing apparatuses including ticket machines and car navigation devices, which are provided with input/output mechanisms such as keys and/or voice, input/output operations must be performed successively when a user wishes to use one or more of their functions. To do so, a program within the information providing apparatus executes interactive input/output operation with a user through passage from one state to another, each state comprising a series of operations of receiving input from the user, acquiring information necessary for the apparatus to perform its function(s), controlling the apparatus, and indicating the progress or result of the state. When viewed from the user, this passage from one state to another could be perceived as an interactive scenario involving exchange of information between the user and the apparatus to achieve an objective. The apparatus has many prepared scenarios corresponding to many of its service functions, and the user inputs commands and information as requested by the apparatus to carry on the interactive scenario(s) to utilize these functions.
The information providing apparatus that executes an interactive scenario prompts the user for appropriate input so that the apparatus can reliably perform particular operation using visual and vocal information in a dialogue involved. If the user input is appropriate, the apparatus moves on to a next scenario. If not, the apparatus does not respond at all or keeps on prompting the user for appropriate input. That is, in a dialogue between the user and the apparatus, it is the apparatus that dictates the major part of the dialogue. The user must always give responses as appropriate as the apparatus so requires, and the apparatus refuses any of them to abort the interaction, unless the user response is appropriate. This scheme of processing interactions which demands appropriate user inputs could be positively evaluated as being easy to operate. However, as the user uses the apparatus more often, a high incidence of input error by the user and of recognition failure by the apparatus occurs to annoy the user, and interactive scenarios also bore the user when played repeatedly. Thus, there is a need to eliminate these shortcomings.